Detection rules › Kusto

OracleDBAudit - Query on Sensitive Table

Status
available
Severity
medium
Time window
30m
Source
github.com/Azure/Azure-Sentinel

'Detects when user queries sensitive tables.'

MITRE ATT&CK coverage

TacticTechniques
CollectionT1005 Data from Local System

Rule body kusto

id: d7fdcad5-ce96-4db6-9a5e-4a86a5166e5e
name: OracleDBAudit - Query on Sensitive Table
description: |
  'Detects when user queries sensitive tables.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: SyslogAma
    datatypes:
      - Syslog
queryFrequency: 30m
queryPeriod: 30m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Collection
relevantTechniques:
  - T1005
query: |
  let sensitive_tbls = dynamic(['table_name1', 'table_name2']);
  OracleDatabaseAuditEvent
  | where isnotempty(DstUserName)
  | where isnotempty(Action)
  | extend TableName = replace(@'[,\(\)]', '', extract(@'(?i)SELECT(.*?)FROM\s(.*?)\s', 2, Action))
  | where isnotempty(TableName)
  | where TableName in (sensitive_tbls)
  | project TableName, DstUserName, DbAction
  | extend AccountCustomEntity = DstUserName
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: AccountCustomEntity
version: 1.0.3
kind: Scheduled

Stages and Predicates

Parameters

let sensitive_tbls = dynamic(['table_name1', 'table_name2']);

Stage 1: source

OracleDatabaseAuditEvent

Stage 2: where

| where isnotempty(DstUserName)

Stage 3: where

| where isnotempty(Action)

Stage 4: extend

| extend TableName = replace(@'[,\(\)]', '', extract(@'(?i)SELECT(.*?)FROM\s(.*?)\s', 2, Action))

Stage 5: where

| where isnotempty(TableName)

Stage 6: where

| where TableName in (sensitive_tbls)

Stage 7: project

| project TableName, DstUserName, DbAction

Stage 8: extend

| extend AccountCustomEntity = DstUserName

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Actionis_not_null
  • (no value, null check)
DstUserNameis_not_null
  • (no value, null check)
TableNamein
  • table_name1 transforms: cased
  • table_name2 transforms: cased
TableNameis_not_null
  • (no value, null check)

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

FieldSource
DbActionproject
DstUserNameproject
TableNameproject
AccountCustomEntityextend